And if it's not, which one do you use, if you use any at all, and why?

I have True Lights and Darkness on a laptop and TLM on this computer. TLM makes it a lot more darker, which actually requires you to have a torch or nighteye enabled, but True Lights adds some pretty colored lights. Can't decide which I like better, but it would be great if I could use both of them at the same time.

Using Lights 300 and Hedgehog's meshes

Both mods make almost the same thing. But I′m using True Light and Darkness with the plugin from TLM modular version which give light sources to npcs at dark places (at night or in caves).
True Light and Darkness comes with a suggested config to your morrowind become darker, if you don′t mind.